Ehnhancement of resource selection for sidelink discontinuous reception (drx) receiver user equipment (ue)

Abstract

A user equipment (UE), including a vehicle to everything (V2X) device, a pedestrian UE, or other UE, a baseband processor or other network device can operate to receive an indication of a sidelink (SL) discontinuous reception (DRX) parameter (e.g., an SL DRX active time) of a receiver UE for SL communication (e.g., Mode-2 SL communication). A resource selection procedure can be performed of a set of candidate resources within a resource selection window (RSW) based on the SL DRX parameter of the receiver UE so that at least a subset of candidate resources of the set of candidate resources satisfies a threshold to be within the SL DRX parameter of the receiver UE. A report of the set of candidate resources can then be transmitted from the physical (PHY) layer to a higher layer to enable the SL communication. The SL communication, for example, can include an autonomous determination of SL resources for a Mode-2 sidelink communication.

1 . A user equipment (UE), comprising:
 a memory; and   a processing circuitry configured to, when executing instructions stored in the memory, cause the UE to:
 receive an indication of a sidelink (SL) discontinuous reception (DRX) parameter of a receiver UE for a SL communication; 
 perform a resource selection procedure to determine a set of candidate resources, wherein the set of candidate resources includes at least a subset of candidate resources satisfying a threshold of the SL DRX parameter of the receiver UE; and 
 use one or more resources from the set of candidate resources to enable the SL communication. 
   
     
     
         2 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 select the at least the subset of candidate resources at a physical (PHY) layer within a resource selection window (RSW) to satisfy the threshold based on the indication of the SL DRX parameter, wherein the threshold comprises at least one of: a portion of reported candidate resources within an SL DRX active time of the receiver UE, a number of reported candidate resources within the SL DRX active time, or a number of candidate slots overlapping with the SL DRX active time.   
     
     
         3 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 determine the threshold based on a preconfigured ratio or a preconfigured number of candidate resources associated with a resource pool; or   determine the threshold based on communication with the receiver UE, wherein the threshold comprises a portion of candidate resources, a number of candidate resources, or a number of candidate slots that overlap with an SL DRX active time of the receiver UE,   wherein the at least the subset of candidate resources is equal to or greater than the threshold.   
     
     
         4 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 determine an RSW based on a total number of sidelink candidate resources (M) within a timed window;   perform sensing of candidate resources to be used for the SL communication during a sensing window before the RSW to decode a physical sidelink control channel (PSCCH);   select an initial candidate resource set according to a reference signal received power (RSRP) threshold based on the RSW and excluding unavailable candidate resources; and   define the at least the subset of candidate resources within the initial candidate resource set that is within an SL DRX active time of the receiver UE based on the threshold.   
     
     
         5 . The UE of  claim 4 , wherein the processing circuitry is further configured to:
 modify a size of the RSW to ensure that a threshold portion of candidate slots, or a threshold number of candidate slots, overlap with the RSW and the SL DRX active time; and   set a remainder portion of candidate slots or a remainder number of slots in the RSW to be after the threshold portion or the threshold number of candidate slots.   
     
     
         6 . The UE of  claim 4 , wherein the processing circuitry is further configured to:
 in response to one or more conditions being satisfied, the one or more conditions including at least one of: the initial candidate resource set being less than a reported portion of the total number of sidelink candidate resources, or a number of subset candidate resources of the at least the subset of candidate resources within the SL DRX active time of the receiver UE being less than a number threshold or a percentage threshold of the reported portion of the total number of sidelink candidate resources:
 perform an iteration of the resource selection procedure by modifying the RSRP threshold, re-selecting the initial candidate resource set based on the RSW and excluding the unavailable candidate resources, and re-defining the at least the subset of candidate resources that is within the SL DRX active time. 
   
     
     
         7 . The UE of  claim 6 , wherein the processing circuitry is further configured to:
 in response to the initial candidate resource set being equal to or greater than a reported portion of the total number of sidelink candidate resources, and a number of subset candidate resources of the at least the subset of candidate resources within the SL DRX active time of the receiver UE being equal to or greater than the number threshold or the percentage threshold of the reported portion of the total number of sidelink candidate resources, and in response to the at least the subset of candidate resources being no less than the reported portion of the total number of sidelink candidate resources:
 in response to the at least the subset of candidate resources being no less than the reported portion of the total number of sidelink candidate resources, report the at least the subset of candidate resources to a higher layer by randomly selecting the reported portion of the total number of sidelink candidate resources or reporting each candidate resource of the at least the subset of candidate resources; and 
 in response to the at least the subset of candidate resources being less than the reported portion of the total number of sidelink candidate resources, randomly select at least one candidate resource in the set of candidate resources that is not in the at least the subset of candidate resources and report both the at least one candidate resource that is randomly selected and each candidate resource of the subset of candidate resources, or report the at least one candidate resource to the higher layer. 
   
     
     
         8 . (canceled) 
     
     
         9 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 perform the resource selection procedure based on an SL DRX active time of the receiver UE by:
 performing sensing of candidate resources to be used for the SL communication during a sensing window while obtaining an initial RSRP threshold associated with the SL DRX active time; 
 restricting an initial candidate resource set to be selected within the SL DRX active time of the receiver UE, while excluding unavailable candidate resources; and 
 in response to the initial candidate resource set being less than a number threshold or a percentage threshold of the reported portion of the total number of sidelink candidate resources, perform another iteration of the resource selection procedure with a modified RSRP threshold to re-define the initial candidate resource set that is within the SL DRX active time, otherwise report the initial candidate resource set; and 
   perform the resource selection procedure based on an SL DRX inactive time of the receiver UE by:
 performing sensing of candidate resources to be used for the SL communication during the sensing window while obtaining an RSRP threshold associated with the SL DRX inactive time; 
 restricting another candidate resource set to be within the SL DRX inactive time; and 
 in response to the another candidate resource set being less than a remainder of the number threshold or a percentage threshold of the reported portion of a total number of sidelink candidate resources, perform another iteration of the resource selection procedure with another modified RSRP threshold to re-define the another candidate resource set that is within the SL DRX inactive time, otherwise report initial candidate resource set and the another candidate resource set. 
   
     
     
         10 . (canceled) 
     
     
         11 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 perform the resource selection procedure, including sensing of candidate resources based on a partial sensing window and an indication of whether a minimum number of candidate slots or a smaller minimum number than the minimum number of candidate slots for partial sensing is enabled or disabled by a resource pool configuration.   
     
     
         12 . The UE of  claim 11 , wherein in response to a number of candidate slots being within an SL DRX active time of the receiver UE satisfying a threshold number of candidate slots, the smaller minimum number is enabled as a minimum of a threshold number of candidate slots or the minimum number of candidate slots, and in response to a number of candidate resources being within the SL DRX active time of the receiver UE, the smaller minimum number is enable as the minimum of a threshold number of candidate resources over a number of sub channels in a resource pool or the minimum number of candidate slots. 
     
     
         13 . The UE of  claim 11 , wherein the processing circuitry is further configured to:
 increase a partial sensing occasion or a number of partial sensing occasions to satisfy the minimum number of candidate slots (Ymin) with a threshold number of the number of partial sensing occasions being within an SL DRX active time of the receiver UE.   
     
     
         14 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 performing a re-evaluation or a pre-emption check of one or more selected candidate resources of the set of candidate resources from the resource selection procedure for an aperiodic transmission by performing a partial sensing, wherein the set of candidate resources starts from the one or more selected candidate resources and ends at a last slot of candidate slots based on slot indices utilized in the resource selection procedure.   
     
     
         15 . The UE of  claim 14 , wherein the processing circuitry is further configured to:
 perform contiguous partial sensing (CPS) as the partial sensing based on a sensing window that is at least M logical slots plus one or more logical slots before a first selected resource of the one or more selected candidate resources, wherein M is up to 31 slots or another preconfigured number of slots; or   perform a periodic based partial sensing (PBPS) based on a periodicity utilized for the resource selection procedure,   wherein the CPS and the PBPS initiate after a resource selection of the set of candidate resources.   
     
     
         16 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 cease SL communication in response to an SL channel busy ratio (CBR) measurement being above a CBR threshold;   wherein the CBR measurement is based on an SL received signal strength indication (RSSI) measured within an SL CBR measurement window; and   in response to a number of SL RSSI measurement slots being below an SL RSSI measurement slot threshold, use a preconfigured SL CBR value for determining whether to cease the SL communication.   
     
     
         17 . (canceled) 
     
     
         18 . A baseband processor comprising:
 a memory, and   a processing circuitry configured to:
 receive an indication of a discontinuous reception (DRX) active time of a receiver user equipment (UE) for a sidelink (SL) communication; 
 perform a resource selection procedure within a resource selection window (RSW) based on the SL DRX active time of the receiver UE to determine a set of candidate resources, wherein at least a subset of candidate resources of the set of candidate resources satisfies a threshold to be within the SL DRX active time of the receiver UE; and 
 select one or more resources from the set of candidate resources to enable the SL communication. 
   
     
     
         19 . The baseband processor of  claim 18 , wherein the SL communication comprises an autonomous determination of SL resources as a Mode-2 sidelink communication. 
     
     
         20 . The baseband processor of  claim 18 , wherein the processing circuitry is further configured to:
 modify the RSW of the resource selection procedure based on a percentage of candidate slots in the RSW overlapping the SL DRX active time satisfying a percentage threshold, or based on a number of candidate slots in the RSW overlapping the SL DRX active time satisfying a number threshold; and   configure a remainder of time slots in the RSW to be after the RSW that overlaps the SL DRX active time.   
     
     
         21 . The baseband processor of  claim 18 , wherein the processing circuitry is further configured to:
 in response to the at least the subset of candidate resources within the SL DRX active time being less than the threshold, or in response to the set of candidate resources being less than a percentage of a total number of candidate resources, increase a reference signal received power (RSRP) threshold to perform another iteration of the resource selection procedure within the RSW; and   in response to the at least the subset of candidate resources within the SL DRX active time satisfying the threshold or the set of candidate resources satisfying the percentage of the total number of candidate resources, report the at least the subset of candidate resources to a higher layer,   wherein the percentage of the total number of candidate resources is configured via a higher layer configuration or parameter.   
     
     
         22 . The baseband processor of  claim 21 , wherein the processing circuitry is further configured to:
 in response to the at least the subset of candidate resources within the SL DRX active time being less than the percentage of the total number of candidate resources, randomly select candidate resources from the set of candidate resources not within the at least the subset of candidate resources; and   report the at least the subset of candidate resources within the SL DRX active time and the candidate resources randomly selected, or only report the set of candidate resources to the higher layer.   
     
     
         23 . (canceled) 
     
     
         24 . A method for resource selection for sidelink (SL) communication:
 receiving, by a user equipment (UE), an indication of an SL discontinuous reception (DRX) parameter of a receiver UE;   performing, by the UE, a resource selection procedure to determine a set of candidate resources, where the set of candidate resources includes at least a subset of candidate resources satisfying a threshold of the SL DRX parameter of the receiver UE; and   use one or more resources from the set of candidate resources to enable the SL communication.   
     
     
         25 . (canceled)